<?php

	$vstup = "https://www.youtube.com/watch?v=9CvYE3UkM-s";
	
	$vystup = substr($vstup, 0, strpos($vstup, 'watch?v=')) . 'embed/' . substr($vstup, strpos($vstup, 'watch?v=') + 8); 
	
	echo $vystup;

?>